I have a 12AY7 preamp project and, in reference to the plate characteristics chart, I can achieve a preferred operating point over a range of plate currents. Are there any advantages to running the tube at a higher current; that is, would you purposely run a higher current draw than you need?

Higher current can create more noise. And drive requirements may increase. I don't see any advantage. Why are you using that tube? The 12AX7 is usually the preferred type, or one of its fancy numbered equivalents, like 7025 and the like.

Tubes are usually more linear when their operating point is chosen so that Iq is higher. Refer to dynamic characteristics graph in tube's datasheet for more information,

__________________modverb, transitive /mod/ to state that one is utterly clueless about the operation of device to be "modded" and into "fixing" things that are not broken; "My new amplifier sounds great so I want to mod it."

Higher current can create more noise. And drive requirements may increase. I don't see any advantage. Why are you using that tube? The 12AX7 is usually the preferred type, or one of its fancy numbered equivalents, like 7025 and the like.

12AY7s have a broader bias range compared to the AX7 at the same B+. In this app I ran out of input headroom with the AX7 and didn't need the higher gain, anyway.